What is the world's fastest single engine turbojet aircraft?- question from Michael Hampshire

There are two primary contenders for the highest speed ever reached by an aircraft carrying a single jet engine.
The first is the American F-106 Delta Dart air defense fighter.
In late 1959, the manufacturer Convair joined the US Air Force in taking one F-106 with the
serial number 56-0459 and modifying it to maximize the plane's record-setting
potential. The goal of this effort, called Project Firewall, was to break the world absolute speed record of
1491.26 mph (2,399.95 km/h) that had been set by a Soviet Ye-152-1 on 7 October 1959. The Ye-152-1 was a special
test version of the MiG-21 fighter that had also been customized to set
speed, altitude, and climb records.

Pilot Joe Rogers with F-106 S/N 56-0459

The improved F-106 completed a number of test flights in early December 1959 with Air Force test pilot Maj. Joseph
Rogers at the controls. During two weeks of testing, Rogers pushed the F-106 to its limits to prove out the
modified design. Unfortunately, each flight was marred by engine compressor stalls that resulted in violent yaw
oscillations. Although engineers and mechanics attempted to adjust the engine and eliminate the undesired
behavior, no successful correction could be found. The test team was forced to remove the modified F-106 from the
program and instead use a standard production vehicle for the remainder of the test effort.

The back-up plane was serial number 56-0467 and made its attempt at the world speed record on 15 December 1959.
During his very first flight in the new F-106, Maj. Rogers successfully broke the record previously set by the
Ye-152-1 and claimed a new speed of 1,525.95 mph (2455.78 km/h) at an altitude of 40,000 ft (12,190 m). That speed
at that altitude equates to about Mach 2.31. The record was set over an
officially recognized straight line course 11 miles (18 km) in length, and Rogers reported that his speed might
have been even higher since the plane was still accelerating as it left the course. For his exploits, Rogers
received the Distinguished Flying Cross, the DeLavaulx Metal, and became the 25th recipient of the Thompson Trophy.

The Soviets, meanwhile, resurrected the Ye-152-1 test aircraft in hopes of recapturing the speed record. The
Ye-152 was based on the earlier Ye-150 and both were developed as improved versions of the MiG-21. The Ye-152A
used two of the engines of the basic MiG-21 with a modified nose inlet and other aerodynamic modifications to
improve rate of climb and maximum speed. The Ye-152-1 was a further modification of the Ye-152A with an enlarged
wing and revised tail design but returning to a single engine layout. Yet another variation was the Ye-152-2 that
tested additional minor modifications to the design.

Two views of the Ye-152-1 test aircraft

These two test aircraft were followed by the definitive Ye-152M that was intended to be the prototype of a new air
defense interceptor. This model featured increased fuel capacity in an enlarged fuselage spine, a more powerful
engine, and a more advanced missile and avionics combination than the earlier MiG-21 series. A further test
aircraft based on the Ye-152M was the Ye-152P that included canards and other aerodynamic features. In spite of
these many concepts and advanced prototypes, the Ye-152 series was eventually abandoned once the Soviet Union
decided to proceed with the MiG-25 instead.

Before the MiG-25 came along to set its impressive speed records, however,
the Ye-152-1 reportedly set a new record of its own about 2½ years after Joe Rogers' Mach 2.31 flight in the
F-106. The feat was said to occur on 7 July 1962 when test pilot Col. G. Molosov achieved a new mark of 1,665.85
mph (2,680.92 km/h), or about Mach 2.51. However, no proof of the flight was offered and the record is still
considered unverified.

To confuse matters even further, the always secretive Soviets reported the name of the plane that set the records
in 1959 and 1962 was not the Ye-152-1 but the Ye-166. Even today, a plane painted as the Ye-166 is on display at
the Russian Central Museum of the Air Forces at Monino
(English site about the Museum) and said to be the
record-setting test aircraft. In actuality, this aircraft is the later Ye-152M and is only painted to represent
the actual Ye-152-1 (aka Ye-166 or E-166). The fate of the actual historic Ye-152-1 is unknown, but perhaps it was
lost in an accident and a similar plane substituted to take its place.

Ye-152M on display at Monino but painted as the Ye-166 (aka Ye-152-1)

The record-setting F-106 too suffered its own inglorious fate. After Joe Rogers used F-106 S/N 56-0467 to exceed
Mach 2.3, the plane was returned to regular service with the Air Force. The plane, the eighteenth F-106 to be
built, was transferred to the 329th Fighter Interceptor Squadron based at George Air Force Base in California. The
plane remained in service for just a couple years after its famous record-setting flight before disaster struck.
As pilot James Wilkinson was taking off on a training flight on 14 August 1961, the right main landing gear tire
blew and the rubber broke apart from the wheel hub.

The pilot and ground controllers decided it would be best to remain airborne and burn off fuel before attempting a
landing at Edwards AFB to the north, which had a longer runway and better crash equipment. Wilkinson landed the
plane on the intact left and nose gear and tried to keep the right gear off the runway as long as possible. Once
the right gear came down, however, the wheel hub quickly sent up a shower of sparks before breaking up and
impacting the wing. This rough landing started a fire in the wing that rapidly grew to consume the entire aft half
of the plane. The pilot successfully climbed out of the cockpit and ran to safety after the F-106 finally came to
a stop, but the plane was unfortunately declared a total loss.

Ironically, the F-106 Joe Rogers had originally flown during Project Firewall does still exist today. F-106 S/N
56-0459, only the seventh model off the assembly line, ultimately became part of the 318th Fighter-Interceptor
Squadron at McChord AFB in Washington where it was retired in 1983. The plane was then donated to the
McChord Air Museum where it remains on display. Many
mistakenly believed that this F-106 was the one Joe Rogers had flown on his record-setting flight in 1959 and were
unaware of the last-minute switch to the back-up aircraft. It was only many years after the plane went on display
that the true story about the flight was discovered and Joe Rogers set the record straight.

Joe Rogers visiting F-106 S/N 56-0459 on display at McChord

Joe Rogers enjoyed a long and successful career in both the Air Force and as a civilian contractor. Joe first
joined the Army Air Corps in 1943 and became a pilot instructor during World War II. His first taste of combat
came in Korea where Rogers claimed a rare kill against a MiG-15 jet while flying a piston-engined P-51 Mustang.
Rogers later transitioned to the jet-powered F-80 Shooting Star and completed nearly 200 missions before the end
of the Korean War. Now holding the rank of Major, Rogers graduated from the USAF Test Pilot School and joined the
F-86D, F-102, and F-106 flight test programs.

Following his record-setting F-106 flight, Rogers returned to front-line duty and took command of the 317th Fighter
Interceptor Squadron flying the F-102. Rogers re-joined the testing world again for a few years when he became a
test pilot for the SR-71 and YF-12. He rounded out his career with over
40 combat missions in Vietnam aboard the A-37 Dragonfly and F-4 Phantom II
before retiring with 29 years of service at the rank of Colonel. Rogers was then hired into the Fighter Division
of Northrop where he helped market the F-5 Tiger family for thirteen
years. Joe Rogers remained passionate about the aerospace world throughout his life until he passed away in 2005.
- answer by Jeff Scott, 23 October 2005

A Third Contender:

A third possible contender for the fastest single-engine turbojet might be the Soviet
MiG-23 fighter developed during the 1960s. Many sources credit the
aircraft with a maximum speed of about Mach 2.35 at an altitude of 36,000 ft (10,975 m). This combination of
Mach number and altitude results in a speed of approximately 1,555 mph (2,500 km/h), which is higher than the
official record set by the F-106.

Mikoyan-Gurevich MiG-23 'Flogger'

Although the MiG-23's mark is still lower than the record claimed by the Ye-152-1, that record remains
unconfirmed. If there is conclusive evidence that the MiG-23 ever achieved Mach 2.35, this aircraft would likely
be considered the world's fastest turbojet. Unfortunately, we have been ubable to locate any records, official or
otherwise, that provide proof the MiG-23 ever actually flew at this speed.
- answer by Greg Alexander, 26 October 2005